Considering the USB 2.0 ports would use a USB EHCI controller and not the standard controller found in the original PS2, they'd be breaking compatibility with all of the games that have used USB previously, plus the EHCI controller would be more expensive to impliment, and the PSTwo is obviously the 'end of life' model to make way for the PSP and PS3.
Thus, I say that USB 2.0 on the PSTwo is bunk (UNLESS they added it to link with the PSP and added some rom0: librarys for EHCI that defaultly override usbd.irx)
If at first you don't suceed, Pull the trigger again.
See bash. See bash run. See bash run GCC. Run, GCC, Run!